Automatic radio control apparatus



April 19, 1949. w. B. BRUENE AUTOMATIC RADIO CONTROL APPARATUS 2 Shets-Sheet 1 Filed Aug. 2, 1946 i dLl WA RRE/Y BY Patented Apr. 19, 1949 UNITED STATES PATENT OFFICE AUTOMATIC RADIO CONTROL APPARATUS Warren B. Bruene, Cedar Rapids, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa, a corporation of Iowa Application August 2, 1946, Serial No. 688,167

7 Claims. 1

This invention relates to radio apparatus and more especially to an improved arrangement for automatically controlling the setting of adjustable circuit elements of radio sets and the like.

A principal object of the invention is to provide a simple and. compact control device for automatically setting a radio control shaft in any one of a large number of angular orientations.

In certain types of radio tuners of which the so-called permeability core tuner is typical, it may be necessary to cause the control shaft of the tuner to undergo more than one complete revolution in order to allow the tuner to cover its complete tuning range. Such tuners may be referred to as multi-turn tuners as distinguished from the usual rotary condenser or single-turn type. In multi-turn tuners, it is necessary therefore to be able to stop the control shaft at any point either during the first complete revolution or during any fractional :part of a succeeding revolution.

Accordingly, it is another principal object of the invention to provide a compact and relative simple arrangement for controlling the selective setting of multi-turn tuners.

A feature of the invention relates to an arrangement for automatically controlling the selective setting of a control shaft in any one of a large number of angular orientations by employing a novel combination of rotary switche and motor control interlocks.

Another feature relates to a simplified automatic shaft setting system employing a plurality of rotary switches for determining respectively the number of complete turns for the control shaft, and an additional fractional turn which the shaft must undergo in arriving at the desired setting.

A further feature relates to the novel organization, arrangement and relative interconnection of parts which cooperate to provide a relatively simple and comp-act automatic tuning control for radio sets and the like.

Other features and advantages not particularly enumerated will be apparent after a consideration of the following detailed descriptions and the appended claims.

In the drawing,

Fig. 1 is a schematic structural and circuit Wiring diagram of an automatic tuning arrangement according to the invention.

Fig. 2 is a side view of the control unit according to the invention.

Fig, 3 is a rear view of the control upit, and

Fig. 4 is a front view of the unit.

Referring to Fig. 1, the block II] represents any well-known radio control element such for example as a permeability tuner, or a rotary condenser the control shaft I I of which is arranged to undergo from a fraction of one revolution to ten complete revolutions in setting the device II]. For example, the device I0 may be associated with a variable frequency oscillator such as conventionally used in radio communication equipment which equipment may be required to selectively transmit on a plurality of separate channels. For example, assuming an oscillator having a range of 500 kilocycles controlled by ten turns of the shaft II, with the system to be described it is possible to select any live kilocycle channel within this 500 kilocycle spectrum. Merely for explanatory purposes, it will be assumed that the shaft I I is capable of making ten complete turns and with selective positions for each turn. In other Words, shaft I I can be selectively positioned in any one of a hundred different angular orientations. For this purpose, shaft II is driven through a slip-friction clutch I2 from any wellknown type of reversible electric motor I3 having an armature I4, and two directional control field wnidings I5, I6. Winding I5 may be considered as the forward control winding (clockwise as indicated in Fig, 1) during which movement the mechanism is undergoing its selective position. The winding I6 will then be the reverse winding which drives the shaft I I to its normal or homing position before the selecting action takes place. Attached to shaft II is a toothed stop wheel II, which has a cooperating stopping arm or pawl i8, pivotally mounted at I9, and normally urged by a spring 20 into the path of the teeth on wheel I'I, so as positively to stop shaft II in the proper selected position. Pawl i8 is associated with an electromagnet 2I which, when energized, moves the pawl away from wheel I I which can therefore freely rotate.

Directly driven from the shaft of motor I3 is a pinion 22 meshing with gear 23, which in turn drives the disc 24 carrying a pin 25. Pin 25 is arranged to engage the spring contact 26 of a limit switch 21, so as to prevent overtravel of the shaft I I when it arrives at its homing or reference position. For this purpose, the gear ratio between 22 and 23 is such that disc 24 makes a single revolution per ten complete revolutions of shaft I I, and the contacts 26 and 21 are not closed until the device I0 is driven under control of winding I e to its homing position.

Driven directly from shaft II is the rotary element 28 of a seeking switch SI which has a series of ten fixed contacts 29-35. This switch is shown diagramatically in Fig. 1, and it will be understood that any well-known form of commutator switch may be employed. For explanatory purposes, the disc 28 may be of metal having a peripheral cutout portion 39 Whose circumferential length is slightly less than the circumferential spacing of the successive contacts 2938. Also: driven directly from shaft I I is a pinion :39 meshing with a gear 41 having the same gear ratio as 22, 23. Gear 4| carries a pin 42 which, at the limit of travel of gear 41 in either direction, is adapted to engage a stopping dog. 43 which is pivotally mounted at M, and has its lower end: movable between rigid stops d5, 46. Dog 43 is spring-pressed by spring 41 and the stops 45,46, are slightly spaced from the arm 43, so as to allow a slight overtravel of disc 4I after pin 42 engages dog 43.

' Directly driven from shaft, 48 is the rotary member 49 of a seeking switch S2 similar to switch SI, and having a set of fixed, contacts arr-5a Associated, with switch SI is a rotary channel identifying switch 33, having a manually or remotely movable brush 6i], and a set of fixed contacts 6.I'I01which are multiplied to the corresponding fixed contacts of switch SI. Likewise, associated with switch S2 is another channel' identifying marking switch S4, having a manually. or remotely movable brush H and a coo-per ating set of fixed contacts l2BI. Switches S2 and S4 cooperate to determine the number of completeturns which shaft II is to undergo; and switches Si, S3, cooperate to determine the additional fractional turn for shaft I I. and reversing. control of the motor It are determined respectively by relay 82 and relay 83, the power supply for the motor and relays being schematically represented by battery 84. In Fig. the various drive. shafts are diagrammatically represented by the dot-dash lines.

The mechanism is shown in Fig. 1 with the shaft II; at rest in a previous selected setting, wherein the fixed contacts 29 and 5B of switches SI and" S2 are ungrounded by reason of their being in registry with the corresponding cutout sectors 39 and 85. of the respective discs 28 and 4.9 When a new setting isrequired for shaft I I, brushes 60 and II are manually or remotely moved to' engage the corresponding identifying fixed; contacts. For example, assume that the new setting requires shaft II to undergo two complete revolutions and to be stopped in the fifth division of the second revolution; in other words,

event, brush II is moved to contact 53' and brush 60 is moved to contact 6.5. Thereupon the ground at brush 'II' is extended to corresponding contact: 5| and the ground at brush (it is extended to corresponding contact 33. The common conductor 86 which is electrically connected' to both discs 28 and 49 is thereupon grounded and completes a circuit over conductor fir'Lcondu'ctor 88, winding of stoprelease magnet 2|; to battery 84'. Another circuit is simultaneously. completed from grounded conductor 87, winding ofrelay 82, to battery 84'. Thus, thestop pa-wl" I8 issrem'oved from engagement with wheel I11 and. relay 82 operates its associated movable contacts. This closes a circuit from battery 34, contacts 88, 89, of relay 82, conductor 90 andmotor armature I 4. A similar circuit is closed from conductor 90, contacts 9!, 92-, of relay 83, thence to ground. through the; reversewinding I 5 of the motor. At the same time, a self-locking The starting i circuit for relay 82 is completed from battery 84, conductor 93, winding of relay 82, conductor 94, contacts 95, 96, conductor 91, to ground through the locking contacts 98, 99, of relay 82. The foregoing described. circuits cause the motor to drive shaft II in a reverse or homing direction until pin 52 engages the stopping dog 13, so as positively to stop any further rotation of the shaft H or the switches Si, S2. When the shaft II is thus positively stopped in its homing position, the disc 24 may continue to rotate by reason of the slip-friction clutch I2 until the pin 25 causes closure of the contacts 26, 21, which thereupon complete the operating circuit for relay 33.

Upon the operation of relay 83, the circuit for motor winding IE is opened, and a circuit for winding I5 is closed from ground through that winding, conductor Iilil, contacts itl and 9I, conductor 90, contacts 89, 88, to battery 8%. A selflocking circuit is also closed for relay 83 traceable from battery 8%, winding of relay 83, conductor I02, contacts H13, 98, conductor 9? to ground through contacts 98, 99. Thus relay 33 remains operated even though limit switch contacts 26, 2i,

" open at the beginning of the forward rotation of disc 24. As a result of the operation of relay 83, the forward winding !5 of the motor is connected in circuit causing the shaft II and the switches S1, S2, to rotate. These switches continue to.

rotate until the particular channel identifying contact in each switch is in registry with the associ'ated' cutout 39, 85. It should be noted that this forward motor drive circuit continues to be closed until both switches SI and S2 reach the previously selected position as determined by the setting of brushes 6t and ll. When both switches reach their selected positions, ground is removed from the common conductor 86, resulting in the deenergization of magnet 2| and the immediate engagement between the pawl I8 and the stopping wheel I I, which has ten teeth corresponding respectively to the ten fixed contacts in theswitch SI, while switch S2 has 10 contacts corresponding to the 10 complete turns that are available for shaft I I.

The intertia of the motor armature I4 causes positive stopping engagement between the toothed wheel I1 and the pawl I8. However, because of the slip-friction clutch I2, the motor may continue to rotate until it comes to rest. At the same time, the removal of ground from conductor 86 opens the normal operating circuit for the start relay 82, whereupon the ground at contact 99 is disconnected from the locking circuit of relay 83 which also becomes shaft I:'I'is to be stopped at position #25. In that deenergized. As a resul, the shaft I I stays in its selected position and the tuning cycle is complete.

It will be noted that during the homing position of the shaft Ii, the switches SI and S2 are rotated in their reverse direction and may come in registry with the previously marked fixed contact. However, this does not cause stopping of either the motor or of the switches since the inclined surface of the teeth on Wheel I'I permits that wheel to rotate past the pawl I3, and because of the inertia of the motor and associated parts, the shaft H continues to coast past the position corresponding to the selected contacts in switches SI and S2. It will be understood of course that this last described action takes place only when the selected contacts in the switches are closer to the respective cutouts 39 and 85 during the reverse rotation as compared with their distance from these cutouts during the selective rotation; In other words, the selective stopping of the switches SI and S2 is effected only during the forward or selective movement of shaft II.

Referring to Figs. 2, 3 and 4, there is shown a typical construction for the control unit of Fig. 1. The parts in Figs. 2, 3 and 4 which are identical with the corresponding parts shown in Fig. 1, bear the same designation numerals. The unit comprises a box-like construction having bottom wall I04, top wall I05, and front and rear walls I06, I01. These latter walls carry suitable bearings for the shafts II, 48, and for the shaft 2311. As shown in Figs. 2, 3 and l, the motor I3 drives a worm I08 and a worm wheel 109, which is fastened to one member of the slip-friction clutch I2, the other member of which is connected to shaft II. The pin 42 on gear 4| engages with the stopping dog 43 to prevent overtravel of the controlled shaft I I, the dog 43 being pivotally attached on a pin 44 supported in a block H0, fastened to base I04, thus permitting gear M to make a full revolution while allowing the shaft II to rotate ten full turns. Pinion 22 and worm wheel I09 are free to rotate on the shaft II with the motor drive to the shaft being delivered through the slip-friction clutch I2, which limits the torque tending to rotate the controlled device I0. The limit switch 2'! is supported on the rear wall I01 and the operating arm of this switch is adapted to be engaged by the pin 25.

While Fig. 1 shows the gear 23 and the disc 24 as separate elements, it will be understood that the pin 25 may be directly attached to the gear 23 as shown in Fig. 2. The turn-determining switch SI has its fixed contacts carried by a suitable insulator plate II I attached by bracket H2, to the top wall I05. The plate III has a central opening which is larger than the shaft l I so as to permit this shaft freely to rotate. The cooperating disc 28 of switch SI is rigidly fastened to shaft II. Likewise, the fixed contact plate I3 of switch S2 is attached by bracket II4 to bottom wall I04 and the cooperating disc 49 is rigidly attached to shaft 48. The curved arrows in Figs. 3 and 4 represent the direction of rotation of the parts during the selective action as distinguished from the direction of rotation during the homing movement.

While one particular embodiment has been described, various changes and modifications may be made without departing from the spirit and scope of the invention.

What is claimed is:

1. An automatic setting control arrangement for radio apparatus and the like, comprising a control shaft to be selectively rotated, a motor for rotating said shaft, stop means for said shaft, a first seeking switch, a second seeking switch, each of said switches having a bank of contacts each contact identifying a particular position of said shaft, means to apply a switch controlling potential to a selected contact in the first switch to start said first switch in operation and to determine the number of complete revolutions for said shaft, means to apply a switch controlling potential to a selected contact in the second switch to start said second switch and to determine the additional fractional revolution said shaft undergoes in order to arrive at said selected position, a motor start relay response to the application of said potentials to said contacts to cause said switches and said shaft to rotate in predetermined fixed ratios until each switch locates said selected contacts, and electromagnetically controlled stop means responsive to said 6 switches finding said contacts for stopping said shaft.

2. An automatic setting control arrangement for radio apparatus and the like, comprising a control shaft to be selectively rotated, a motor for rotating said shaft, a first seeking switch, a second seeking switch, each switch having a bank of contacts each contact identifying a particular position of said shaft, the contacts in said first switch determining the number of complete revolutions for said shaft, the contacts in the second switch determining the additional fractional revolution for the shaft to arrive at its desired setting, means to apply a switch controlling potential to a selected bank contact in each switch to start its seeking operation, a motor start relay responsive to said potential for first causing said motor to rotate said shaft to a normal reference point and then to rotate said shaft until it is selectively stopped in response to both said switches finding said selected contacts.

An automatic setting control arrangement for radio apparatus and the like, comprising a control shaft to be selectively rotated, a motor for rotating said shaft, a first seeking switch, a second seeking switch, each switch having a bank of contacts with each contact identifying a particular position for said shaft, means to apply a switch starting and seeking control potential to a selected contact in each switch bank, motor start control relay, a motor reverse control relay, an electromagnetically controlled stop for said shaft, an electric circuit responsive to said potential for causing said motor to rotate said shaft in a homing direction and simultaneously releasing said shaft from said stop means, means automatically effective when said shaft reaches its homing position for reversing the shaft rotation and for causing said switches to seek said contacts to which said potential has been applied, and means effective when both said switches have found said contacts to operate said stopping means to stop said shaft in its selected position.

An automatic setting arrangement according to claim 3 in which said shaft stopping means includes a toothed wheel fastened to the shaft and an electromagnetically controlled pawl which is shiftable into and out of engagement with the teeth on said Wheel.

5. An automatic setting control arrangement according to claim 3 in which each of said switches includes a rotatable member, and the means for automatically reversing the rotation of said shaft after it reaches its homing position includes a rotatable limit switch element means to drive said element in synchronism with the rotatable member of one of said switches, and a slip-friction clutch, between said driving means and said limit switch element.

6. An automatic setting control arrangement for radio apparatus and the like, comprising a control shaft to be selectively rotated to a desired setting, a reversible electric motor for said shaft, a motor start relay, a motor reverse relay, a limit switch which is arranged to be operated when said shaft is rotated to a home position to reverse the motor rotation, a toothed stop wheel fastened to said shaft, a. rotatable member driven from said motor for operating said limit switch, a slip-friction clutch for enabling said shaft to be stopped while allowing said rotatable member to continue rotating to operate said limit switch, a, first seeking switch having a rotatable contact member which is driven from said motor at the same rate as the rotatable member of the limit switch, a

7. second. seeking switch having a rotatable contact member which is driven at the same rate as said shaft, and motor start and reverse control circuits controlled jointly by said seeking switches.

7. An automatic setting control arrangement for radio apparatus and the like, comprising a control shaft to be selectively rotated to a desired setting, a reversible electric motor for said shaft, a first seeking switch having a rotatable member, a second seeking switch having a rotatable member, a toothed stop wheel fastened to said shaft, means to rotate the rotatable member of the first switch at the same rate as said stop wheel and the rotatable element of the second switch at a slower rate, a first channel identifying switch having its bank contacts multipled to the bank contacts of the first seeking switch, a second channel identifying switch having its bank contacts multipled to the bank contacts of the second seeking switch, means responsive to the selective grounding of a bank contact in each of said identifying switches for closing a circuit to said motor to cause said shaft and the rotatable elements of both said seeking switches to move to a home position, a, limit switch connected to said motor through a slip-friction, clutch and rotatable at substantially the same rate as the rotation of said rotatable member of said second switch and for controlling the reverse movement of said motor, said limit switch closing the reverse motor control circuit only after the rotatable elements ofv both said seeking switches have reached home position, a stop member for said stop wheel which is inefiective to stop said wheel during the said,

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date.

1,123,067 Barkhausen et a1. Dec. 29, 1914 1,508,796 Kaminski Sept, 16, 1924 2,085,442 Newell June 29, 1937 2,205,170 Johnson June 18, 1940 2,285,414 Collins June 9, 1942 

